论文部分内容阅读
【目的】研究分离自川中丘陵地区大豆根瘤菌的遗传多样性和系统发育。【方法】采用16S rDNA PCR-RFLP和16S rRNA基因、glnII、共生基因(nodC)系统发育分析的方法进行研究。【结果】供试未知菌的16S rDNA用4种限制性内切酶(HaeⅢ、HinfⅠ、MspⅠ及TaqⅠ)酶切后获得5种16S遗传图谱类型。16S rDNA PCR-RFLP结果表明,所有供试菌株在83%水平分为慢生根瘤菌属(Bradyrhizobium)和中华根瘤菌属(Sinonrhizobium)两大类群,而75%的菌株为中华根瘤菌。6个代表菌株的16S rDNA、glnII和nodC三个位点基因的系统发育结果基本一致,4株与S.fredii USDA205T相似度最高;有2株分别与B.yuanmingense CCBAU10071T、B.diazoefficiens USDA110T相似度最高。4个Sinonrhizobium代表菌株16S rDNA、glnII序列相似度分别为98.3%-99.9%、98.2%-100%,但它们的nodC基因序列完全相同。【结论】川中丘陵地区大豆根瘤菌具有较丰富的遗传多样性,S.fredii为优势种。
【Objective】 The objective of this study was to investigate the genetic diversity and phylogeny of soybean rhizobia isolated from the hilly area of central Sichuan. 【Method】 16S rDNA PCR-RFLP, 16S rRNA gene, glnII, and nodC phylogenetic analysis were used to study the method. 【Result】 Five 16S rDNA sequences of 16S rDNA of unidentified bacteria were digested with four restriction enzymes (HaeⅢ, HinfⅠ, MspⅠ and TaqⅠ). The result of 16S rDNA PCR-RFLP showed that all the tested strains were divided into two groups of Bradyrhizobium and Sinonrhizobium at the level of 83%, while 75% of the strains were Sinorhizobium. The phylogenetic results of six representative 16S rDNA, glnII and nodC genes were basically the same, and the four strains showed the highest similarity with S.fredii USDA205T. Two of them had similarities with B.yuanmingense CCBAU10071T and B.diazoefficiens USDA110T highest. The similarity of the 16S rDNA and glnII sequences of the four representative strains of Sinonrhizobium were 98.3% -99.9% and 98.2% -100%, respectively, but their nodC gene sequences were identical. 【Conclusion】 Rhizobium japonicum in the hilly area of Sichuan Province is rich in genetic diversity and S.fredii is the dominant species.